Insight into oxygen reduction activity and pathway on pure titanium using scanning electrochemical microscopy and theoretical calculations.

HYPOTHESIS: Unlike noble metals, the oxygen reduction reaction (ORR) behavior on Ti is more complicated due to its spontaneously formed oxide film. This film results in sluggish ORR kinetics and tends to be reduced within ORR potential region, causing the weak and multi-reaction coupled current. Though Ti is being used in chemical and biological fields, its ORR research is still underexplored. EXPERIMENTS: We innovatively employed the modified reactive tip generation-substrate collection (RTG/SC) mode of scanning electrochemical microscopy (SECM) with high efficiency of 97.2 % to quantitatively study the effects of film characteristics, solution environment (pH, anion, dissolved oxygen), and applied potential on the ORR activity and selectivity of Ti. Then, density functional theory (DFT) and molecular dynamics (MD) analyses were employed to elucidate its ORR behavior. FINDINGS: On highly reduced Ti, film properties dominate ORR behavior with promoted 4e- selectivity. Rapid film regeneration in alkaline/O2-saturated conditions inhibits ORR activity. Besides, ORR is sensitive to anion species in neutral solutions while showing enhanced 4e- reduction in alkaline media. All the improved 4e- selectivities originate from the hydrogen bond/electrostatic stabilization effect, while the decayed ORR activity by Cl- arises from the suppressed O2 adsorption. This work provides theoretical support and possible guidance for ORR research on oxide-covered metals.

Endoscopic nasal surgery for mucocele and pyogenic mucocele of turbinate: Three case reports.

BACKGROUND: Cases of turbinate mucocele or pyogenic mucocele are extremely rare. During nasal endoscopy, turbinate hypertrophy can be detected in patients with turbinate or pyogenic mucocele. However, in many instances, differentiating between turbinate hypertrophy and turbinate mucocele is difficult. Radiological examinations, such as computed tomography (CT) or magnetic resonance imaging (MRI), are essential for the accurate diagnosis of turbinate mucocele. Herein, we report three cases of mucocele or pyogenic mucocele of turbinate, including their clinical presentation, imaging findings, and treatments, to help rhinologists understand this condition better. CASE SUMMARY: Three cases of turbinate and pyogenic mucocele were encountered in our hospital. In all patients, nasal obstruction and headache were the most common symptoms, and physical examination revealed hypertrophic turbinates. On CT scan, mucocele appeared as non-enhancing, homogeneous, hypodense, well-defined, rounded, and expansile lesions. Meanwhile, MRI clearly illustrated the cystic nature of the lesion on T2 sequences. Two patients with inferior turbinate mucocele underwent mucocele lining removal, while the patient with pyogenic mucocele underwent endoscopic middle turbinate marsupialization. The patients were followed up on the first, third, sixth month, and 1 year after discharge, and no complaints of headache and nasal congestion were reported during this period. CONCLUSION: In conclusion, both CT and MRI are helpful in the diagnosis of turbinate or pyogenic mucocele. Additionally, endoscopic nasal surgery is considered to be the most effective treatment method.

The expression patterns of Nogo-A, myelin associated glycoprotein and oligodendrocyte myelin glycoprotein in the retina after ocular hypertension: the expression of myelin proteins in the retina in glaucoma.

Nogo-A, a major myelin inhibitory protein, inhibits axon growth and synaptic function in the central nervous system. Glaucoma is a progressive neuropathy as a result of retinal ganglion cell (RGC) death. Synaptic degeneration is thought to be an early pathology of neurodegeneration in glaucoma and precedes RGC loss. Here experimental ocular hypertension model was induced in adult rats with laser coagulation of the episcleral and limbal veins. The expression of Nogo-A, myelin-associated glycoprotein (MAG) and oligodendrocyte myelin glycoprotein (OMgp) in the retina was investigated using immunohistochemistry and Western blotting. We found that Nogo-A was expressed in the RGCs and upregulated after the induction of ocular hypertension. OMgp was only expressed in the inner plexiform layer. There was no MAG expression in the retina. Our data provided, for the first time, the expression patterns of three myelin proteins in the adult retina and suggested an important role of Nogo-A in the RGC death and synaptic degeneration in glaucoma.

[Increasing expression of microglia in the retina after optic nerve transection in rats].

OBJECTIVE: To investigate the expression of microglia after optic nerve transection in rats. METHOD: Thirty healthy adult female SD rats were randomly grouped to experimental and control groups according to the random number table. The experimental group received an optic nerve transection (ONT) on their right eyes. ONT was performed 1.5 mm from the eye ball. The control group received a surgery on day 5. Rats were killed 7 days after the first operation. Retinal ganglion cells (RGC) were retrograde labeled by placing fluorogold dye on the stump of the optic nerve. Microglia was immunohistochemically stained in the retinas of normal and 7-day injury groups using ionized calcium adaptive molecular 1 (Iba-1) as the marker. The protein levels of Iba-1 in the retinas were also examined using Western blotting. The number of RGCs was quantified using flatmount of retinas in the two groups. RESULTS: There were some resting microglia (Iba-1 positive cells) in the nerve fiber layer and inner plexiform layer in the normal control retina. However, microglia showed a moderately activated morphology with increased Iba-1 immunoreactivity in the stroma and processes up to outer plexiform layer. Western blotting showed that the levels of Iba-1 was lower in the normal retina and increased to 2.3-fold 7 days after injury (t = 7.669, P = 0.001). The number of RGCs after injury was (1182 ± 64) per mm(2), decreased to 51% in the normal groups (t = 23.85, P < 0.0001). CONCLUSIONS: The results implicated that microglia was increased and partially activated after the optic nerve transection. This may be a manifestation of the self-protection mechanism of RGCs against the injury insult.

Plagiochin E, an antifungal bis(bibenzyl), exerts its antifungal activity through mitochondrial dysfunction-induced reactive oxygen species accumulation in Candida albicans.

BACKGROUND: Plagiochin E (PLE) is an antifungal macrocyclic bis(bibenzyl) isolated from liverwort Marchantia polymorpha L. Its antifungal mechanism is unknown. To elucidate the mechanism of action, its effect on mitochondria function in Candida albicans was studied. METHODS: We assayed the mitochondrial membrane potential (mtDeltapsi) using rhodamine 123, measured ATP level in mitochondria by HPLC, and detected the activities of mitochondrial F(0)F(1)-ATPase and dehydrogenases. Besides, the mitochondrial dysfunction-induced reactive oxygen species (ROS) production was determined by a fluorometric assay, and the effects of antioxidant L-cysteine on PLE-induced ROS production and the antifungal effect of PLE on C. albicans were also investigated. RESULTS: Exposure to PLE resulted in an elevation of mtDeltapsi, and a decrease of ATP level in mitochondria. The ATP depletion owed to PLE-induced enhancement of mitochondrial F(0)F(1)-ATPase and inhibition of the mitochondrial dehydrogenases. These dysfunctions of mitochondria caused ROS accumulation in C. albicans, and this increase in the level of ROS production and PLE-induced decrease in cell viability were prevented by addition of L-cysteine, indicating that ROS was an important mediator of the antifungal action of PLE. CONCLUSIONS: PLE exerts its antifungal activity through mitochondrial dysfunction-induced ROS accumulation in C. albicans. GENERAL SIGNIFICANCE: The effect of PLE on the mitochondria function in C. albicans was assayed for the first time. These results would conduce to elucidate its underlying antifungal mechanism.

Influences of copper speciation on toxicity to microorganisms in soils.

OBJECTIVE: To investigate the relationship between copper speciation and microbial features (microbial communities and copper tolerance level) in order to determine the adverse effect of different forms of Cu on microorganisms. METHODS: Tessier's sequential extraction procedure was used to qualify the different Cu forms (exchangeable, carbonate bound, Fe/Mn oxide bound, residue and organic matter bound), and the copper tolerance level (expressed as IC50, influence concentration) was measured by the plate-count method. RESULTS: By simple correlation analysis, the IC50 was positively correlated with the concentration of exchangeable Cu (R2 = 0.8204), while weakly correlated with other forms of Cu. CONCLUSION: The bacterial community tolerance increases in the copper-contaminated soil while sensitive bacteria decrease in the copper-contaminated soils. The exchangeable Cu exerts high toxicity to microbial communities.

Colon-specific delivery tablets of sodium 4-aminosalicylic acid.

AIM: To prepare a new oral colon-specific delivery formulation and to investigate the release profile in vitro and the colon-specific delivery property in vivo in dogs. METHODS: Sodium 4-aminosalicylic acid was selected as the model drug. The combination of Eudragit RL30D and RS30D were used as sustained-release film, and Eudragit FS30D used as enteric film, which was expected to release drug depending on pH and time. The release profile of tablets was studied in three phosphate buffers with the pH 6.5, 7.0 or 7.4 for 12 h after a simulated gastric presoak for 2 h in 0.1 mol x L(-1) HCl. The tablets were radiolabelled with 99mTc to make their release times and positions in the gastrointestinal tract be followed using a gamma camera. RESULTS: For the in vitro study, there was no drug released in 0.1 mol x L(-1) HCl for 2 h, and release occurred slowly when pH was above 6.5. Drug was released faster while pH was higher. For the in vivo study, the coated tablets remained intact in the upper gastrointestinal tract, and drug release began after the colonic arrival. The uncoated tablets, however, disintegrated in the stomach of the dogs rapidly. CONCLUSION: The coating could protect the drug until the tablets reached the ascending colon, where drug was released slowly for over 10 h.

De novo characterization of Japanese scallop Mizuhopecten yessoensis transcriptome and analysis of its gene expression following cadmium exposure.

BACKGROUND: Japanese scallop has been cultured on a large-scale in China for many years. However, serious marine pollution in recent years has resulted in considerable loss to this industry. Moreover, due to the lack of genomic resources, limited research has been carried out on this species. To facilitate the understanding at molecular level immune and stress response mechanism, an extensive transcriptomic profiling and digital gene expression (DGE) database of Japanese scallop upon cadmium exposure was carried out using the Illumina sequencing platform. RESULTS: RNA-seq produced about 112 million sequencing reads from the tissues of adult Japanese scallops. These reads were assembled into 194,839 non-redundant sequences with open reading frame (ORF), of which 14,240 putative amino acid sequences were assigned biological function annotation and were annotated with gene ontology and eukaryotic orthologous group terms. In addition, we identified 720 genes involved in response to stimulus and 302 genes involved in immune-response pathways. Furthermore, we investigated the transcriptomic changes in the gill and digestive gland of Japanese scallops following cadmium exposure using a tag-based DGE system. A total of 7,556 and 3,002 differentially expressed genes were detected, respectively, and functionally annotated with KEGG pathway annotations. CONCLUSION: This study provides a comprehensive transcripts sequence resource for the Japanese scallop and presents a survey of gene expression in response to heavy metal exposure in a non-model marine invertebrate via the Illumina sequencing platform. These results may contribute to the in-depth elucidation of the molecular mechanisms involved in bivalve responses to marine pollutants.

Autologous bone marrow stem cell transplantation in critical limb ischemia: a meta-analysis of randomized controlled trials.

BACKGROUND: Amputation-free survival (AFS) has been recommended as the gold standard for evaluating No-Option Critical Limb Ischemia (NO-CLI) therapy. Early-phase clinical trials suggest that autologous bone-marrow derived cells (BMCs) transplantation may have a positive effect on patients with NO-CLI, especially decreasing the incidence of amputation. However, the BMCs therapeutic efficacy remains controversial and whether BMCs therapy is suitable for all CLI patients is unclear. METHODS: We conducted a meta-analysis using data from randomized controlled trials (RCTs) by comparing autologous BMCs therapy with controls in patients with critical limb ischemia, and the primary endpoint is the incidence of amputation. Pubmed, EBSCO and the Cochrane Central Register of Controlled Trials (to approximately July 25, 2012) were searched. RESULTS: Seven RCTs with 373 patients were enrolled in the meta-analysis. Because serious disease was the main reason leading to amputation in one trial, six studies with 333 patients were finally included in the meta-analysis. Pooling the data of the final six studies, we found that BMCs therapy significantly decreased the incidence of amputation in patients with CLI (odds ratio (OR), 0.37; 95% confidence interval (CI), 0.22 to 0.62; P = 0.0002), and the efficacy had not significantly declined within 6 months after BMCs were transplanted; OR, 0.33; 95%CI, 0.16 to 0.70; P = 0.004 within 6 months and OR, 0.30; 95%CI, 0.11 to 0.79; P = 0.01 within 3 months. The rate of AFS after BMCs therapy was significantly increased in patients with Rutherford class 5 CLI (OR 3.28; 95%CI, 1.12 to 9.65; P = 0.03), while there was no significant improvement in patients with Rutherford class 4 (OR 0.35; 95%CI, 0.05 to 2.33; P = 0.28) compared with controls. The BMCs therapy also improved ulcer healing (OR, 5.83; 95%CI, 2.37 to 14.29; P = 0.0001). CONCLUSIONS: Our analysis suggests that autologous BMCs therapy has a beneficial effect in decreasing the incidence of amputation and the efficacy does not decrease significantly within 6 months after BMCs transplantation. Patients with Rutherford class 5 are suitable for BMCs therapy, while the efficiency in patients with Rutherford 4 needs further evaluation.

[Effects of population distribution pattern and irrigation schedule on radiation utilization in winter wheat farmland].

A field experiment was conducted in 2006-2008 to study the effects of different population distribution pattern and irrigation schedule on the radiation utilization in a winter wheat farmland at the same population density (2.04 x 10(6) plant x hm(-2)). Four population distribution patterns were designed, i.e., row spacing (cm) x plant spacing (cm) 7 x 7 (A), 14 x 3.5 (B), 24.5 x 2 (C), and 49 x 1 (D), and each pattern had four irrigation schedules, i. e., no-irrigation, irrigation at jointing stage, irrigation at jointing and heading stages, and irrigation at jointing, heading and filling stages. The irrigation amount was 0.60 m3 each time. In the patterns A and B, the tiller number and leaf area index (LIA) were significantly higher than those in C and D (P< 0.05). With the increase of row spacing, the photosynthetically active radiation (PAR) transmittance ratio increased gradually, while the PAR capture ratio had a decreasing trend. Increasing irrigation times increased the tiller number and LAI, but decreased the transmittance ratio of PAR, resulting in a significant increase of PAR capture ratio (P<0.05). The PAR capture ratio in the crop canopy was higher in upper layers, compared with that in lower layers. Relatively uniform population distribution and irrigation increased the PAR capture ratio in the upper 40 cm canopy layers significantly. The radiation use efficiency (RUE) decreased with increasing row spacing, with the two year's average total RUE in A, B, C, and D being 1.24%, 1.27%, 1.21% and 1.06%, respectively, and that in B was 5.21% and 19.56% higher than that in C and D, respectively, with the difference being significant. It was suggested that relatively uniform population distribution improved the winter wheat population structure and PAR capture, being beneficial to the fully use of radiation, and irrigation also had positive effects on the population structure, being helpful to the increase of crop RUE.